Sheet stacker

ABSTRACT

The sheet stacker having a supporting frame and two sets of conveyor belts for conveying a shingled stream of sheets therebetween and into an upwardly growing stack of sheets. One set of belts terminates adjacent the stack, and the other set of belts extends across the bottom of the stack to convey the sheets into the stack. A rotatable member exists at the terminal end of the one set of belts, and sheet-advancing mechanism is mounted on and driven by the terminal end of the one set of belts to engage the stream of sheets and urge them into the stack. A pivotally mounted support arm mounts the terminal end of the one set of belts, and an adjustable support extends from the rotatable member and down to the stream for supporting the sheet-advancing means in an adjustable manner. The sheet-advancing mechanism is in the form of a roller, and small belts extend from the roller to the rotatable member on the terminal end of the one set of belts, for driving the roller and for engaging the stream to advance it into the stack. Adjustable support floors extend beneath the spaced-apart belts in the other set of belts for curving the stream as it approaches the stack, and the sheetadvancing means is therefore also adjustably mounted to be positionable along with the adjustment of the support floors.

Unite States Patent Stobb et al.

[ Dec. 25, 1973 SHEET STACKER [76] Inventors: Anton R. Stobb; Walter J. Stobb,

both of R1). No. 1, Pittstown, NJ.

[22] Filed: Apr. 14, 1972 [21] Appl. No.: 244,199

[52] US. Cl 271/186, 271/188, 271/212 [51] Int. Cl B65h 29/18 [58] Field of Search 271/68, 76, 87, 75, 271/69, 86; 214/6 B, 6 A; 93/93 [56] References Cited UNITED STATES PATENTS 3,436,073 4/1969 Christmas 271/76 1126,1104 4/1966 Hoffswell 271/68 3,051,332 8/1962 Richert et a1 271/68 X 3,692,304 9/1972 de Ridder 271/86 X 3,373,666 3/1968 Crampton 271/46 X 3,327,597 6/1967 Donahue et a] 93/93 R Primary Examiner--Evon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Arthur J. l-lansmann [57] ABSTRACT The sheet stacker having a supporting frame and two sets of conveyor belts for conveying a shingled stream of sheets therebetween and into an upwardly growing stack of sheets. One set of belts terminates adjacent the stack, and the other set of belts extends across the bottom of the stack to convey the sheets into the stack. A rotatable member exists at the terminal end of the one set of belts, and sheet-advancing mechanism is mounted on and driven by the terminal end of the one set of belts to engage the stream of sheets and urge them into the stack. A pivotally mounted support arm mounts the terminal end of the one set of belts, and an adjustable support extends from the rotatable member and down to the stream for supporting the sheet-advancing means in an adjustable manner. The sheet-advancing mechanism is in the form of a roller, and small belts extend from the roller to the rotatable member on the terminal end of the one set of belts, for driving the roller and for engaging the stream to advance it into the stack. Adjustable support floors extend beneath the spaced-apart belts in the other set of belts for curving the stream as it approaches the stack, and the sheet-advancing means is therefore also adjustably mounted to be positionable along with the adjustment of the support floors.

6 Claims, 7 Drawing Figures SHEET STACKER This invention relates to a sheet stacker, and, more explicitly, it relates to a stacker for receiving sheets, such as folded signatures, which are delivered from a printing press and a folding mechanism in a shingled stream deposited onto a conveyor which moves the sheets into a stack.

BACKGROUND OF THE INVENTION Sheet stackers are now fairly commonly used in the printing industry, and this includes stackers or collectors or packer boxes which receive printed and folded sheets of paper and conveys them to a receiver or table where the sheets are stripped from their stream form and are formed into a neat stack of sheets. One example of such prior art is shown in my own U. S. Pat. No. 3,188,082 where a stream of sheets or signatures is conveyed around an inverting drum or conveyor and underneath an upwardly developing stack of sheets. Another prior art patent is U. S. Pat. No. 3,436,073 and still another is U. S. Pat. No. Re26,004. Another example of a prior disclosure is found in my U. S. Pat. No. 2,884,243 where the belts are offset relative to each other but at the location where the belts extend across the stack, rather than in the stream leading up to the stack.

Stackers are basically concerned with receiving sheets as they are doled off the folding mechanism and onto a conveyor which leads the sheets to the stacker. The printing press and folder can operate at high speeds, and it is therefore important that the stacker be operable at a speed to keep up with the production of the printing press and the folder. Also, it is important that the stacker be arranged so that the operator can conveniently pick up portions of the stacked sheets and place them on trucks or other tables in order to keep the production moving. Thus a stacker which moves at a high speed and which produces an upwardly growing stack by having the stream enter at the bottom of the stack, is a convenient and very acceptable type of stacker. Stackers of this general type are already known, however there is still a problem in some form of stackers to have the stacker simplified in structure and yet capable of the efficient performance mentioned.

Specifically, the prior art stackers have been concerned with positively controlling and thereby moving each sheet from its stream form to its stacked relation, and to do so such that the stack is rapidly but neatly formed. In some instances, it has been found that to only have conveyor belts moving the stream beneath the stack is not sufficient control and movement of the sheets to have them form in a neat stack. In those certain stackers and instances, the stack is not properly formed and therefore the operator must still resort to the old method of picking up a pile of the sheets of the ill-formed stack and jog the sheets to have them form a neat stack. Additionally, in these certain instances and with regard to some stackers, the structure and stacker function are such that the stream frequently bunches up and does not continuously and smoothly flow into the stack. This of course causes interruption of production, and it can even cause damage and breakdown of the stacker apparatus, such as the belts used in the conveyors.

Accordingly, it is an object of this invention to provide a stacker which operates at the desired high speed and which positively controls the sheets until they are placed in their stacked form, and the stack is neatly formed.

A more specific object of this invention is to provide a stacker which positively engages the leading end and also the trailing end of each sheet in its stream form to move each sheet from its stream form and into the stack. In accomplishing this object, the engagement of the trailing edge of the sheet is maintained for a maximum length of time so that positive engagement is retained with the trailing edge until virtually the time when the sheet is in its final stacked form. Also, in accomplishing this object, the stacker of this invention is of a simplified construction which is inexpensively manufactured and maintained, and it is also compact and easy to operate and only a minimum of parts are required so that the likelihood of breakage of the apparatus is only minimal.

Still another specific object of this invention is to provide a stacker which accomplishes the aforementioned objectives and overcomes the aforementioned problems and which moves the sheets in a firm manner, such as by curving the sheets in the direction transverse to their direction of movement, at a time prior to when the sheets are in their final stack form, so the sheets can therefore be firmly moved into the stack to provide the desired neat stack.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of one embodiment of a stacker of this invention.

FIG. 2 is an enlarged plan view of a fragment of the stacker of FIG. 1.

FIG. 3 is a view of the shaft of FIG. 2.

FIG. 4 is an enlarged side elevational view of a fragment of the stacker of FIG. 1, and with the view being taken from the side opposite that of FIG. 1.

FIG. 5 is a view of one part of the stacker, with the part being included in FIGS. 1 and 2.

FIG. 6 is a side elevational view similar to FIG. 4 but showing a different embodiment of the stacker.

FIG. 7 is an end elevational view of a portion of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a stacker made according to this invention, and it further shows a shingled stream of sheets 10 which move in the direction of the arrow 11 and which ultimately are formed into the stack 12. That is, the stream 10 is composed of a plurality of sheets 13 which were dropped onto a conveyor, such as the belt 14 trained on the pulley 16 for movement in the direction of the arrow shown thereon, and the sheets 13 are thus shingled in their stream l0 so that the sheet leading edges 17 are on top of the stream and thus the sheet trailing edges 18 are on the bottom of the stream. That is, since the sheets R3 are dropped onto the conveyor 14 as the sheets 13 are doled out of a folder mechanism or the like, they naturally fall into the position shown and described relative to the shingled relation and to the leading and trailing edges of the sheets.

The stream 10 is then further conveyed along by means of a conveyor I9 which is in the form of a set of conveyor belts. The belts 19 are trained on a pulley 21 and a drum 22 rotatably mounted with a shaft 23, and the belts 19 continue over the pulleys 24, 26, 27, 28, and over idler pulleys 29, 3i, and 32. lt will be further seen and understood that the rotatable parts just described and over which the belts 19 are trained are all suitably supported, such as by the stacker frame pieces shown, including the pieces 33, 34, 36, and arms 37 and 38 suitably supported from the frame piece 39.

When the stream 16 reaches the bottom of the drum 22, the stream is engaged by a belt 41 which moves in the direction of the arrow 42 and which is trained around the drum 22 and which is also trained over the pulley 43 and the idler pulley 44, as shown. Thus the conveyor belts 41 contact the upper side of the stream 10, and it will be further seen and understood. that the belts 41 therefore contact the sheet leading edges 17. The two sets of belts 19 and 41 then convey the stream to the top of the drum 22 and thereby invert the stream so that the sheet leading edges 17 are on the bottom of the now inverted stream 10. With that sheet orientation relative to the stream 10, the sheets can be sequentially moved into the stack 12 and underneath the stack 12 to where the leading edges 17 abut a stop 46 and the sheets are then stripped from their stream relation and are formed into the stack 12. lt will therefore be clearly understood that the sheet leading edges 17 can slip into the stack 12 while the sheet leading edges 18 are on top of the stream 10 and are therefore accessible for engagement and pushing or tucking the sheets 13 into the stack 12. Also noticeable in this arrangement is the fact that the belts 41 extend beyond the stack 12 and thus beyond the stop 46 which is suitably mounted on the stacker frame, and therefore the stop 46 strips the sheets from their stream relation and forms them into the stack 12.

FIG. 1 further shows that a drive mechanism, such as a pulley or sprocket 47 is suitably mounted on the frame piece 34 by means of the shaft 48 on which the pulley 28 is also mounted. A timing belt or sprocket chain 49 is trained on the member 47 and is also trained on a circular member 51 mounted on the shaft 23 along with the drum 22. Thus, suitable drive to the shaft 48 will induce the obvious rotation of the rotatable members 28 and 47 on the shaft 48, and there will then be consequent drive to the two sets of belts l9 and 41 for the movement described.

With more specific regard to this particular invention, it will be seen that the endless belts 19 extend to and thus turn around or terminate at the location adjacent the upstream side of the stack 12 and that is by virtue of the pulley or rotatable member 24. One arrangement for this terminal is most clearly shown in FIGS. 1, 2 and 4 where a shaft 52 is shown supported on the spaced-apart arms 38 and which in turn supports a plurality of rollers 53 which are rotatably mounted on the shaft 52. FIG. 2 thus shows four such pulleys 53, and it will here also be seen that there are thus four belts 19.

FIGS. 1 and 4 show that the belts 19 rotate the pulleys 53, and sheet-advancing means, in the form of a roller 54, is rotated by virtue of and in accordance with the rotation of the pulley S3, in each of the four instances. The roller 54 is rotatably mounted on two side plates 56 which are on each side of the pulley 53 and which are piloted on the shaft 52 in the milled pairs of slots 57 in the shaft 52. Thus the plates 56 may be bronze plates having a center opening 60 for snugly nesting the plates in the slots 57 by virtue of the spacedapart legs 59 on the plates 56. The extending ends of the plates 56 have semi-circular notches 61 which nest with the reduced circular ends 62 of the rotatable member or pin 54, which is most clearly shown in FIG, 5. A belt 63 is trained on each end of the pulley 53 and on each end of the rotatable member 54, as shown in FIGS. 2 and 5, and thus there is a rotation drive member, in the form of the belt 63, extending from the pulley 53 and to the rotatable member 54.

FIG. 4 further shows that the member 54 and the belt 63 are positioned adjacent the set of belts 41, and thus the member 54 and the belts 63 engage the top of the sheet stream Ml and, by virtue of the direction of motion of the member 54 and the belt 63, as shown by the arrow 64, the sheets 13 are pushed or tucked into the stack 12. Of course it will be further seen and understood that the member 54 is very small in diameter, compared to the diameter of the pulley 53, and thus the member 54 is snugly positioned in the juncture between the stream 10 and the stack 12, in the position shown in FIG. 4. in fact, it has been found that the member 54 can be as small as one-quarter inch in diameter so that it can engage the sheet trailing edges 18 until the very last possible moment in the process of tucking the sheets 13 into the stack 12. It will also be understood that, depending upon physical pressure of the roller or member 54 and of the belts 63 in the downward direction, and thus against the stream 10, and, due to the inherent resilience of the stream 10 by virtue of its paper characteristic, both the roller 54 and the belt 63 would engage the stream 10, and thus both would serve in the nature of sheet-advancing members or means in tucking the sheets into the stack. Also, the sheet-advancing means described has a linear speed, which is the speed at which they contact the stream 10, which is the same as the linear speed of the leading edges 17 of the sheets as they are moved underneath the stack 10 and under the influence of the belts 41. Thus there is no buckling or jam-up of the sheets at the entrance to the stack 12, as there might be if the sheetadvancing means described were operating'at a linear speed greater than the speed of the stream 10.

If desired, there may be a joining pin 66 extending between each set of plates 56 on each pulley 53, for structure uniformity and stability.

FIG. 4 further shows that there is an adjusting screw 67 extending threadedly in the shaft 57 and in the plane of each of the plates 56 for abutting the semi-circular surface 68 on each plate 56 and thereby being available for forcing the plates 56 away from the axis of the shaft 52 and thus serve as a positioner for the roller 54, and more particularly serve as a belt tightener for the belts 63. Also, the shaft 52 is mounted on the spaced-apart arms 38 and is rotatably adjustable thereon, and the position of rotation is held by means of a set screw 69 threaded in each arm 38 and abutting the end of the shaft 52, in a conventional arrangement. This permits selective positioning and adjustment of the roller 54 relative to the lower belts 41 and relative to the stack 12 according to the upstream side 71 of the stack 12. Still further, additional adjustment can be made by virtue of the fact that the support arms 38 are themselves pivotal relative to the stacker frame piece 37. Thus, the arms 38 are up and down pivotally mounted on a shaft 72 supported on the stacker frame piece 37, and set screw 73 extending threadedly in the arms 38 can abut the shaft 72 to determine the set pivoted position of the arms 38, and thus determine the elevation of the sheetengaging means and the pulleys 53.

FIG. 4 further shows that there is a support floor or table 74 over which the belts 41 can extend and thus on which the stack 12 is supported. The upstream end 76 of the piece 74 extends under the roller 54 so that the roller 54 can be operable relative to the piece 74 in that it can exert downward pressure on the piece 74 through the belts 63 and stream and the belts 41. Further, in this arrangement, the belts 63 serve as sheet-advancing means, in that they engage the top of the stream 18, and they also serve as a rotation drive member between the pulleys 53 and the rollers 54.

Still further, additional adjustment or selective positioning of the sheet-advancing means can be achieved by virtue of pivotal mounting of the frame piece 37 which is shown in FIG. 1 to be supported on a shaft 77 and to be held thereto by means of a set screw 78, in a conventional arrangement of shaft and set screw.

FIGS. 6 and 7 further disclose the arrangement described in connection with FIGS. 1 through 5, and it additionally discloses a somewhat modified arrangement for extent and support of the four belts 41. That is, FIG. 7 now clearly shows four belts 41, and it would be understood that there could be a different number of belts 41. Likewise, it will also be understood that there could be a different number of belts 19, such as two belts 19 rather than the four belts 19 shown.

FIGS. 6 and 7 thus show the basic structure described, but they additionally show the support floors 81 and 82 to be somewhat different from the table 74 which may also be four strips or floors 74, such as the four floor strips 81 and 82 as seen in FIG. 7. In FIG. 6 it will be further noticed that the drum 22 is located to the right, relative to its location in FIG. 4, and thus the floors 81 and 82 have a greater extent between the top of the drum 22 and the entrance or stack near side 71. Additionally, FIGS. 6 and 7 show that the belts 41 can be offset relative to a horizontal plane, such as shown in the drawing, and thus the sheets 13 will be curved in a plane transverse to their direction of stream movement, as indicated in FIGS. 7 which shows the bottom of the stack 83 curved as a paper product might curve in a somewhat irregular pattern when bowed as described, and the top of the stack 83 would ultimately seek its planar position to be perhaps straight as shown in FIG. 7. Of course bowing the sheets 13 at the location between the drum 22 and the stack edge 71 will stiffen the sheets 13 and thus permit them to be better handled in forcing them into the stack 83.

To accomplish the bowing of the sheets at a time while they are still in the stream relation and even prior to when they are moved into their position beneath the stack 83, the supports 81 and 82 are extended, and the support 81 is shown in an elevation higher than that of the support 82. Further, the supports 81 and 82 are shown to be vertically adjustable as they are mounted on guide pins 84, and a screw 86 extends in the frame piece 39 and the upper end of the screw 86 abuts the bottom of the support floor 81 for determining the elevation of the floor or table 81. This of course vertically positions the corresponding conveyor belt 41, and thus the bowing of the stream 10 is controlled and can be set as desired. In the arrangement in FIGS. 6 and 7, there may be four sheet-advancing means, such as shown in FIG. 2, one for each of the four belts 19, or, as previously mentioned, there may be a different number,

such as only two, of the sheet-advancing means, and that would likely be with the two center belts 19. Of course if there are four sheet-advancing means consisting of the rollers 54 and endless belts 63, one set for each of the four belts 19 in the embodiment in FIGS. 6 and 7, then the plates 56 and the attending parts described would be arranged so that the roller 54 would be immediately above the belt 41 on the upper support floor 81, as would be obvious to one skilled in the art.

It is also important to notice that FIGS. 4 and 6 show the sheet-advancing belts 63 to extend into the horizontal plane of the lower belts 41, and it will be understood that the belts 63 thus flank the belt 41. With this arrangement, the belts 41 and 63 can get a firm grip on the sheets 13 at the moment that the sheets are being tucked into the stack 12. That is, the common arrangement of having the belts 41 and 19 of the same width can be employed, and thus the belts 63 will flank each belt 41, as shown and mentioned. Of course this is not to say that the intervening stream 10 would not interfere with the precise flanking described, but depending upon the stiffness of the stream 10, as determined by the thickness and character of the paper therein, the belts 63 would be in a position to bend the stream over the respective belts 41, and this is best shown and disclosed in the manner described in connection with FIGS. 4 and 6.

The compactness of the stream 10 is controlled in part by a pressure roller 87 which is rotatably mounted above the pulley or cylindrical roller 21 and on the standard 88. Thus the roller 87 may be positioned to press the stream downwardly against the roller 21, and the roller 87 may be vertically adjustable in any conventional manner of mounting in its position to accommodate different thicknesses of stream and to provide different compressions of the stream.

What is claimed is:

1. A sheet stacker for collecting and piling sheets of paper into an upwardly growing stack of the sheets and from a shingled stream of sheets extending underneath said stack, comprising two sets of conveyor belts for en gaging respective opposite faces of the stream of sheets and holding them therebetween and conveying them toward the stack of the sheets at the bottom thereof, a stop at the downstream end of the stream for stopping the sheets in their stream movement and causing them to form the stack of sheets, one of said sets of belts extending to an end position adjacent the side of the stack at the entrance of said stream into said stack for conveying the sheets up to the stack, a cylindrical rotatable member adjustably disposed adjacent the stack for supporting said one of said sets of belts at the said end position and being rotated by said one set of belts and being adjustable toward and away from said stream, the other of said sets of belts being in contact with the streamleading edges of said sheets, a roller of an outer diameter smaller than that of said rotatable member and rotatably disposed adjacent the entrance of the stream to the stack at the juncture between said stream and said stack for moving the sheets into the stack, a plurality of endless belts operatively engaged with said rotatable member and with said roller for rotating said roller by and in direct relation to the rotation of said rotatable member, adjustable mounting means operatively connected with said rotatable member and said roller for adjustably positioning said roller and said endless belts relative to said rotatable member and to selective locations and pressures of contact with the stream of sheets. 2. The sheet stacker as claimed in claim 1, wherein said endless belts are trained on said rotatable member and said roller and extend beyond the surface of said roller for engagingsaid sheets immediately adjacent the stack.

3. The sheet stacker as claimed in claim 2, wherein there is one of said endless belts on each side of the belt in said one set of belts, for engaging the sheets at spaced-apart locations on said sheets.

4. The sheet stacker as claimed in claim 1, wherein said rotatable member is supported on a shaft which is adjustably positionable relative to said other set of belts for selective settings toward and away from said other set of belts, and said adjustable mounting means being supported on said shaft and being swingable and extendable therefrom and extending to said roller for supporting and positioning said roller relative to said shaft.

5. The sheet stacker as claimed in claim 1, wherein said other set of belts consists of a plurality of spacedapart belts offset relative to each other for curving the stream transverse to its direction of flow, there being more than one said roller, with one of said rollers being for each of said spaced-apart belts and being offset in accordance with the ofiset of said spaced-apart belts. and a support floor for each of and disposed beneath each of said spaced-apart belts and their said rollers for slidably guiding said spaced-apart belts.

6. The sheet stacker as claimed in claim 5, including adjustable mountings for said support floors for adjustably positioning said support floors at different elevations relative to each other for curving the stream, and said adjustable mounting means for said rollers being positionable toward and away from said support floors. 

1. A sheet stacker for collecting and piling sheets of paper into an upwardly growing stack of the sheets and from a shingled stream of sheets extending underneath said stack, comprising two sets of conveyor belts for engaging respective opposite faces of the stream of sheets and holding them therebetween and conveying them toward the stack of the sheets at the bottom thereof, a stop at the downstream end of the stream for stopping the sheets in their stream movement and causing them to form the stack of sheets, one of said sets of belts extending to an end position adjacent the side of the stack at the entrance of said stream into said stack for conveying the sheets up to the stack, a cylindrical rotatable member adjustably disposed adjacent the stack for supporting said one of said sets of belts at the said end position and being rotated by said one set of belts and being adjustable toward and away from said stream, the other of said sets of belts being in contact with the stream-leading edges of said sheets, a roller of an outer diameter smaller than that of said rotatable member and rotatably disposed adjacent the entrance of the stream to the stack at the juncture between said stream and said stack for moving the sheets into the stack, a plurality of endless belts operatively engaged with said rotatable member and with said roller for rotating said roller by and in direct relation to the rotation of said rotatable member, adjustable mounting means operatively connected with said rotatable member and said roller for adjustably positioning said roller and said endless belts relative to said rotatable member and to selective locations and pressures of contact with the stream of sheets.
 2. The sheet stacker as claimed in claim 1, wherein said endless belts are trained on said rotatable member and said roller and extend beyond the surface of said roller for engaging said sheets immediately adjacent the stack.
 3. The sheet stacker as claimed in claim 2, wherein there is one of said endless belts on each side of the belt in said one set of belts, for engaging the sheets at spaced-apart locations on said sheets.
 4. The sheet stacker as claimed in claim 1, wherein said rotatable member is supported on a shaft which is adjustably positionable relative to said other set of belts for selective settings toward and away from said other set of belts, and said adjustable mounting means being supported on said shaft and being swingable and extendable therefrom and extending to said roller for supporting and positioning said roller relative to said shaft.
 5. The sheet stacker as claimed in claim 1, wherein said other set of belts consists of a plurality of spaced-apart belts offset relative to each other for curving the stream transverse to its direction of flow, there being more than one said roller, with one of said rollers being for each of said spaced-apart belts and being offset in accordance with the offset of said spaced-apart belts, and a support floor for each of and disposed beneath each of said spaced-apart belts and their said rollers for slidably guiding said spaced-apart belts.
 6. The sheet stacker as claimed in claim 5, including adjustable mountings for said support floors for adjustably positioning said support floors at different elevations relative to each other for curving the stream, and said adjustable mounting means for said rollers being positionable toward and away from said support floors. 